Portable battery charger



FIG. 1 is a top perspective view of a portable battery charger showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a right side elevational view thereof.

The broken lines displayed in the figures depict environmental structure for illustrative purposes only and form no part of the claimed design. 

The ornamental design for portable battery charger, as shown and described. 